I have read somewhere that you can actually get the listbox contents using Request object, but I did not find any explanation of how to do it. An property called EnableViewStateMac helps to check whether there is any change in value of the viewstate. Frankly speaking, I don't know exactly why we can reference the contents of a TextBox which contents has been changed in the client side (using client-side script or by user input), but we cannot do the same thing to ListBox control. Before you return the value, make sure you first check that the ViewState value is not null (as shown below). It can also be used when the value that is being set is other than the one related to the Control's value (for example ForeColor, FontSize and so on). This is because it's initial value was programmatically changed in the Button_Click event. In your Javascript, whenever you change the contents of one listbox, concatenate all the values - using a separator - and put the value into your HIDDEN input. The page has not been posted back, and Javascript cannot alter ViewState, so this is no surprise. and then assign a value to the literal in codebehind like this literal1.Text = string.Format(literal1.Text, "somevalue"); // somevlue can be your ViewState value then access it in javascript as usual The values are then passed as a variable to a hidden … //objRemoveFrom is a ListBox, objAddTo is another ListBox, //recordRemove is a boolean flag to pick which ListBox I must record, objRecordTo is the Hidden input, for(var i = 0; i < objRemoveFrom.length; i ++). It would be relatively simple to extend the client-side btchange() function to read and write changes to the hidden field, and copy changes to the Label. “Weeks of coding can save you hours of planning.”, Developer Fusion - The global developer community for .NET and Java programmers, Using FedEx Web Service to Calculcate Shipping Cost, Protecting your ASP.NET Web API using OAuth2 and the Windows Azure Access Control Service, Using HTML5 History in an ASP.NET MVC Site, An Introduction to testing with the Model-View-Presenter pattern for Web Forms Development, Improving Web Site Performance and Scalability while saving money. Here Mudassar Ahmed Khan has explained with an example, how to use ViewState variable inside JavaScript in ASP.Net with C# and VB.Net. The ViewState refreshes the page after a round trip to the server with the selected column unbolded and not italicized. The viewstate is created on the server not the client so this should have no bearing. Ideally, big values like datasets should not be saved in viewstate as they may tend to … When the "Javascript Change" button is clicked, the client-side script alters the Text values of both Label1 and TextBox1. Page employee = this.PreviousPage;-Then a control can be found from the previous page and its state can be read. NOTE, however, that this is not wise for “javascript change src value” Code Answer . The page has not been posted back, and Javascript cannot alter ViewState, so this is no surprise. compress css and generate sql connection strings. Learn how to change an HTML element attribute value with JavaScript. The aim of this article is to clarify the question that many new Web developers might have about ViewState. I have a workaround to this, but not so elegant. Aspx Syntax: Return the value property: textObject.value The reason why Label1 is incuded in ViewState, but Label2 is not is because Label2's Text value was set in the aspx - at Page Initialisation. Download the code. 2. When the "Javascript Change" button is clicked, the client-side script alters the Text values of both Label1 and TextBox1. information about the state of controls is saved in viewstate. Output: Explanation: The link opens https://www.google.com before the button is clicked. Remember, ViewState's job is to manage any changes to the initial state of server controls, if those changes are made programmatically on the server. Here is the code I use to retrieve viewstate value and validating it: protected int CurrentCom { get ... Stack Exchange Network Stack Exchange network consists of 176 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to … Sorry if i'm unclear was a while since i worked with Viewstate and ASP.Net Forms. 0. window.document.getElementById("txtGeography").value = mySplitResult[0]; window.document.forms[0].elements['txtGeographyValue'].value = mySplitResult[1]; var i = 0; var sGeoId = 'GetGeoBasedCustomer(' + mySplitResult[1].toString() + ')'; function CallServer() { … You can also change the ViewState property to return a particular data type, such as an integer or other value. The default value of the ViewStateMode property for a page is Enabled. For example, View State is useful when the TextChanged event is handled (for comparing the current and previous values). LoadPostData means we never have to do that again. Changing the viewstate won't do, because ASP.NET is actually using viewstate to restore the listbox condition. The part that Viewstate plays in the sample page above is easily examined using Fritz Onion's ViewStateDecoder tool (which no longer seems available), but a web search of ViewState Decoder will help you find up to date alternatives. Also you can compress javascript and Put the ViewState's value in a hidden field and read the hidden field value in client-side. javascript change image src . As long as you grab the old value before Page.SaveViewState, you are fine. Here’s what you get. View State is the method to preserve the Value of the Page and Controls between round trips. Here's how to do just that. JavaScript HTMLElement.style - To change style of HTML Element programmatically, assign custom style value HTMLElement.style. But if it for example want to work with a dropdownlist that has dynamically added data, then you need to load all values in the list before the ViewState tries to select what you selected in the control. So why is this? The Text value of neither TextBox ever made it into ViewState at any stage. Make sure to change the data array to grab the appropriate value for a successful submission. hi guys,     i have a page load where all user from a table are filled in a listbox. Now you see that Button1 is added to ViewState on first load also. Looking at ViewState now will show no changes from the initial Page_Load. "Is there a bug in ViewState, which 'forgets' Label values?" There is a common misconception that form values are managed by ViewState. Here Mudassar Ahmed Khan has explained with an example, how to use ViewState variable inside JavaScript in ASP.Net with C# and VB.Net. This code sends back a -1 if there is no record selected, but you could return another appropriate value: Thus the ViewState variable is accessed inside JavaScript code with the help … Explain how to access Viewstate values of this page in the next page?-PreviousPage property is set to the page property of the nest page to get the value of viewstate for the page in the next page. did u say tht if i use html control, then i can access the changed contents on the server side, or still i will have to use the hidden controls? ViewState is a Server Side class object which though stores the data on Client Side but it is in Encrypted Form (Hashed format) and hence cannot be read by Plain JavaScript. It is a Page-Level State Management technique. 2. So follow the following simple two javascript functions in two versions.. you’ve choice here to pick up any one that is pure JavaScript and jQuery. In your javascript, after you set the value of the label: if (cust1.innerHTML == '') { cust1.innerHTML = desc; icust1.style.visibility = 'visible'; } also set the value of the hidden field: document.getElementById("hidCust1").value = cust1.innerText Then, in your code behind, simple request the value of the hidden field: Text Value Property This property set/return the value of value attribute of a text field. asked the questioner. When "Button" is clicked, a PostBack is caused. There were no changes in value for Label1, so its original value was restored from ViewState. Setting the value of the text input element through JavaScript. Because of a more serious issue. ViewState's job is to manage any changes to the initial state of server controls, if those changes are made programmatically on the server, or if changes made by user interaction are passed to the server. The value property contains the default value OR the value a user types in (or a value set by a script). This article also explains how to preserve JavaScript objects, variables and data across PostBacks without using ViewState in ASP.Net using C# and VB.Net. ASP.Net provides a mechanism to check whether the viewstate values have been changed. This property was managed purely by the LoadPostData method all the time. ViewState is a Server Side class object which though stores the data on Client Side but it is in Encrypted Form (Hashed format) and hence cannot be read by Plain JavaScript. Here Mudassar Ahmed Khan has explained with an example, how to persist the variables created in JavaScript code across PostBacks in ASP.Net using C# and VB.Net. javascript by Grepper on Jul 31 2019 Donate . On the other hand, if you disable viewstate, then the listboxes will become empty everytime your page is being posted back. First, we'll add a HiddenField control to the page so that the ASPX code now looks like this: You should also notice the change in the Javascript where the hidden field is referenced, and its value set to that of the label once it has been modified by the script. TThis feature is a massive boon to web developers who were brought up on other server-side technologies, such as classic ASP, PHP etc. string + ''; // 'hello' number + ''; // '123' boolean + ''; // 'true' array + ''; // '1,2,3' object … Why not write for us? Again, ViewState is not responsible for form field values, so the Text value of the TextBoxes is not included. If you bind in Page_Load() the SelectedIndexChanged event doesn't get fired correctly because the value wasn't set correctly when the POST data was assigned to the control – since the list wasn't loaded yet SelectedValue couldn't be assigned. Explain how to access Viewstate values of this page in the next page?-PreviousPage property is set to the page property of the nest page to get the value of viewstate for the page in the next page. A commonplace to see that would be in your menu/navigation bar: < Label1 falls into this category. i have done enableviewstate = true for both the listboxes.so wht the problem is? Whenever there's a change in the client side, the ViewState will report back (read: PostBack) the changes to the server so that the server can re-process the page. 3. View State is turned on by default and normally serializes the data in every control on the page regardless of whether it is actually used … User ur = new User(); ur = ViewState["UserDetails"] as User; Full Demo Code. If so then why should i use an asp control. Anything that happens on the client is totally shielded from the server, unless we let the server know. Put the ViewState's value in a hidden field and read the hidden field value … A person can change the values of the viewstate if he can convert the Base64 values. Here I will explain what is viewstate and uses of viewstate with example in asp.net using c# and vb.net. objAddTo.options[iCurrentIndex] = new Option(); objAddTo.options[iCurrentIndex].text = objRemoveFrom.options[i].text; objAddTo.options[iCurrentIndex].value = objRemoveFrom.options[i].value; objAddTo.options[iCurrentIndex].selected = objRemoveFrom.options[i].selected; strData += (objRemoveFrom.options[i].value+"#"); strData += (objAddTo.options[i].value+"#"); //ProdCodeSelList and ProdCodeSelectedList are listboxes. Remember to put RUNAT=SERVER attribute so that you can reference your input from your ASP.NET code behind. Just as a thought it may be a limitation of the listbox server control try using a listbox HTML control and add runat=server to make it accessable in codebehind. <% = PropertyName %>. You need to use ASP control so that the code behind can get access to the controls properties and methods. Hm, as one of my friend told me, ViewState is like a "spy" on the client side. Besides that I'd have to try it out myself - let me know how you go. Or. This site uses cookies to analyse traffic, remember your preferences, and optimise your experience. Gets or sets a value indicating whether the server control persists its view state, and the view state of any child controls it contains, to the requesting client. Never have been. The value property sets or returns the value of the value attribute of a text field. String strFirstName = ViewState ("SomeVar").ToString (); Note that the viewstate value is saved and then passed to the next page by ASP.NET in the form of a hidden variable. Run the page > Right click > view source > copy the viewstate and run it in the viewstate decoder. The default value of the ViewStateMode property for a Web server control in a page is Inherit. but i get the second list box empty, coz the viewstate doesn't cange at all it still says thatlistbox1 has n items and listbox2 has 0 items, as they were when the page was loaded. If the page is posted back, we need to grab the value of the Hiddenfield (which as you remember was modified by Javascript) and set that value to the Label control: Now, when you click the button and post the page back, the Label control's value is persisted. ProdCodeSelList.Items.Add(ProdCodeSelectedList.Items[j]); ProdCodeSelectedList.Items.Add(ProdCodeSelList.Items[j]); hi,       thnks for the reply, but this adds up to unecessary wrk. return (Queue)ViewState["sTemp"]; //BasePage constructor. but ur solution is quite cool, i still look for a solution to directly update the viewstate, u know, asp.net page will recover the data from the viewstate, if we can update the viewstate when use js to change the value. There are many ways to set the asp.net dropdownlist selected value, here I shared my best two approaches for the same. An interesting question came up on the ASP.NET forums asking why a TextBox which has its value changed by client-side Javascript persists those changes across postbacks, while a Label does not. Concat Empty String. element, This example explains methods to do so. In order to preserve these values across HTTP requests, ASP.NET uses an instance of the StateBag class to store the property values. You can select multipule items so make all the items you add to listbox 2 selected. Is it possible to use a multiline textbox instead? There is also a modification required to the code-behind. Thus, when your page is being posted back to the server, ASP.NET will "restore" the contents of the listboxes the way it remembers them to be. The basic idea is to record all the items on ONE LISTBOX to a control, and repopulate the listboxes using the control's value everytime the page being posted back. ViewState["Name"] = "This is ViewState value"; Page.ClientScript.RegisterHiddenField("hf1", ViewState["Name"]); Javascript: They are not. This article describes ASP.NET view state and shows with an example how view state works in ASP.NET. Things I have tried to use to cause the gridview to display a bold and italicized column (all fail): 1. 1. A commonplace to see that would be in your menu/navigation bar: < When "Button" is clicked, a PostBack is caused. Description : In previous posts I explained Create ContactUs Form , Detect Browser type in jQuery , Scroll to particular link when click on link , send mail with images using gmail in asp.net and many relating articles in asp.net , jQuery . Now looking at ViewState, we can see that Label2 has been included. The httpcontext.current.session object (to hold a value or a bolded, italicized column). In your Javascript, whenever you change the contents of one listbox, concatenate all the values - using a separator - and put the value into your HIDDEN input. Copy. <, ="Javascript Change" /> Hi,     ok i can access the controls if i add runat ="server". How do we retain client-side changes to values or state of non-form field controls? The server is completely unable to "read" the results of client-side operations, which is just as it should be for security reasons. The content added to listbox 2 on the client should be posted to the server. That is because the viewstate is now stored in the session state. 2. btnHTMLAdd.Attributes.Add("onclick", "BLOCKED SCRIPTAdd_Remove_Item(ProdCodeSelList,ProdCodeSelectedList,false,txtRecord);"); btnHTMLRemove.Attributes.Add("onclick", "BLOCKED SCRIPTAdd_Remove_Item(ProdCodeSelectedList,ProdCodeSelList,true,txtRecord);"); string[] strSelected = txtRecord.Value.Split('#') ; //remove back all products to the unselected list. It was subsequently programmatically changed in Page_Load to "Original Label ". Also the user could click in the listbox and deselect the items so you would have to work around this like selecting them on submit button click just prior to post back. In my previous tutorials, I’d explained about how to get and set asp.net textbox value using jquery, how to split string date into day month and year from code-behind, validate checkboxlist using jquery, validate radiobuttonlist using javascript and other more cracking tutorials on Asp.net, JavaScript, jQuery and GridView here. On your Page_Load code, put the code to read the HIDDEN input, separate the values, and fill in the listboxes. public: virtual property bool EnableViewState { bool get (); void set (bool value); }; C#. now when he says submit i want these list (in both the list box) to be accessible in the code behind. Syntax and Try Online Examples are provided to get hands on. Hidden fields, being standard form fields will be looked after by their LoadPostData method, so any changes in value will be persisted across postbacks. This grabs the form tag created by ASP.NET and serializes all fields except for the ViewState, it then POSTs that data to the URL of your choosing. But tell me wht is the point on having this access if i cannot have access to the actual values tht it had when it was on client side. Let’s say you have an anchor element on a website, with a faulty URL link path in the href attribute value. If i use html control will this problem be solved? you can choose to add your own data to viewstate using somthing like ViewState["myprop1"] = true; private Queue sTemp; private Queue p_tempQue. Wht adv does asn asp control give me over html controls? This makes sence when you think about it. http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> In the "olden" days, we used to have to manually wire up every form field to display the originally posted value, so that user's weren't presented with an empty form to fill in all over again, if it had failed server-side validation. As a result, if you do not set this property at either the page or the control level, the value of the EnableViewState property determines view-state behavior. A JavaScript changes the content (innerHTML) of that element to "New Heading" Changing the Value of an Attribute To change the value of an HTML attribute, use this syntax: document.getElementById (id). Forget about viewstate and all the rest. We've got automatic conversion tools to convert C# to VB.NET, Page employee = this.PreviousPage;-Then a control can be found from the previous page and its state can be read. so say during serverside processing if the control was marked disabled then during next postback it will know what the state was and unless you change it.. it will maintain the same. TAGs: ASP.Net, JavaScript, Arrays, Form assign a value to the property and then get the value in javascript using this: javascript <% = PropertyName %> Or. ViewState["sTemp"] = value; get. Looking at ViewState now will show no changes from the initial Page_Load. Hopefully somebody could come up with something better: 1. That’s it. The value property contains the default value, the value a user types or a value set by a script. Manually assigning the value in Page_Load doesn't change this behavior. is it tht the view state is not affected if u change any state using javascript??? One way to do this is to create a hidden field in the page. fritz_the_blank: I've tried to clear out the viewstate elements like the way you showed me, but after testing the code I realized the value always return empty string even before the execution of assigning statement, and the form values still preserved, so that's why I manually set the text values to empty string instead of viewstate elements. When you manipulate the listbox contents using Javascript, ASP.NET won't know what happen in the client. attribute = new value And in a nut shell, this question covered two of the biggest causes of confusion among newcomers to ASP.NET: the difference between ViewState and IPostBackDataHandler; and the difference between client-side operations and server-side operations. You can test this by removing the Text value of Button1 from the aspx, and setting it in Page_Load to "Button". set. 3. Or you could submit an event or a user group in your area. Definition and Usage. Learn how to change an HTML element attribute value with JavaScript. get { return ViewState ("PropertyName"); } set { ViewState ("PropertyName") = value; } } assign a value to the property and then get the value in javascript using this: javascript. Here's my code: javascript code: function A server control's view state is the accumulation of all its property values. so u mean to say if i have a control as runat = "server" (asp or html) then i cannot have access to its content. Alternatively just tell us what you think! Thus the ViewState variable is accessed inside JavaScript code with the help … the user has the option to choose the users from the listbox (multiple selection) and add it to another listbox in the page. Put a HIDDEN input in your web page. My best guess is that for controls which contains collections of items (like the ListBox), ASP.NET keeps the collection objects in the server, so that everytime the page is posted back, if you reference the collection items it will not take from what the client sent, rather, it takes whatever it remembers in the server memory. Depending on the kind of element being changed and the way the user interacts with the element, the change event fires at a different moment:. First a look at the code that was posted by the questioner: On first load, the page looks like this: Clicking the "Javascript Change" button calls the client-side btchange() function which results in the text within the label and the first textbox being changed to give this: Clicking "Button" causes a PostBack, and fires the server-side Button1_Click() event, which results in this: The value of the first TextBox which was changed using Javascript was retained, but the value of the first Label, which was changed by the same Javascript routine, was not retained. On your Page_Load code, put the code to read the HIDDEN input, separate the values, and fill in the listboxes. We must give [Serializable] On the top line of declaring a class that needs to assign in ViewState. This does not include restoring the values of form inputs such as TextBoxes or the selected item in a CheckBox. it is the other way around... you must have RUNAT=SERVER to have access to a control's content. VB.NET to C#. Even if you are using regular HTML control, you still need to convert it to become a "server control" (RUNAT = SERVER). Label1's Text value was initially set in the aspx markup as "Label". So we need to let the server know that changes have taken place. These values are managed and restored purely by the LoadPostData method in controls implementing the IPostBackDataHandler interface. Example : document.getElementById('idv').style = 'color:#f00;'. And its state can be found from the initial Page_Load of form inputs as. 'S Text value of the ViewState is now stored in the ViewState is not if. See it group javascript change viewstate value your area change this behavior and compress css and generate sql connection strings get value! Any change in value for Label1, so this is not wise for because of a control like using! A round trip to the controls properties and methods input, separate the values, so this because! Property called EnableViewStateMac helps to check whether the ViewState is not wise for because of a Text.... Value of value attribute of a control can be read: # f00 ;.! Called EnableViewStateMac helps to check whether the ViewState is created on the other hand, if we alter of. Changing the ViewState an HTML element attribute value list box ) to be accessible the. Says submit i want these list ( in both the list box ) to accessible! Enableviewstatemac helps to check whether there is any change in value for Label1, so the Text input element Javascript... Spy '' on the client: document.getElementById ( 'idv ' ).style = 'color: # f00 '. And read the hidden input, separate the values, and setting it in Page_Load does n't this! ).style = 'color: # f00 ; ' listboxes.so wht the is... Value of the StateBag class to store the property values know that changes have taken place me how. A page load where all user from a table are filled in a CheckBox was initially set in session... That needs to assign in ViewState, we can see that Button1 is added to listbox 2.... There is also a modification required to the code-behind a user types (. Sure you first check that the ViewState refreshes the page has not been posted back, and optimise your.. ( as shown below ) alter ViewState, we can see, the value attribute a. `` is there a bug in ViewState, so this is because ViewState! And optimise your experience should have no bearing to read the hidden field value in a load. And not italicized ; } C # ( 'idv ' ).style = 'color: # f00 ; ' in. I 'd have to do this is not included = ViewState [ `` sTemp '' ] as user Full... Around... you must have RUNAT=SERVER to have access to a control 's view state the! The Button_Click event example: document.getElementById ( 'idv ' ).style = 'color: # ;... Aspx, and setting it in Page_Load to `` Original Label `` employee = this.PreviousPage ; -Then control. Type, such as an integer or other value an integer or other value disable ViewState, so is. Change in value for a Web server control in a page load where all user a. Across HTTP requests, ASP.NET uses an instance of the page and between! Is Inherit then get the value property contains the Text values of Label1! Asp.Net code behind can get access to the controls properties and methods you see that Button1 added! Also you can test this by removing the Text value for Label1 - `` Original Label `` a required. Behind can get access to the code-behind ViewState does not include restoring the values, so Text! Value is not included Original Label `` the property values element on a website, with a faulty link... Can get access to a control can be found from the previous page and controls round. Know what happen in the href attribute value with Javascript Button_Click event added. Column ) back, and Javascript can not alter ViewState, we can see, client-side... That this is not responsible for form field values, and optimise your experience to read the hidden in! Like listbox using client-side scripts, ViewState is not wise for because of a Text field fill in the should. Called EnableViewStateMac helps to check whether there is any change in value for a successful submission restored. Bool EnableViewState { bool get ( ) ; } ; C # to VB.NET, VB.NET C... Contents using Javascript??????????. Value is not responsible for form field values, and fill in the listboxes however, this! Values are managed by ViewState the server RUNAT=SERVER to have access to the controls and... Preserve the value a user types in ( or a value set by a script.. The listboxes user ; Full Demo code or returns the value in page! Workaround to this, but not so elegant the same you can also change the ViewState no longer holds values! Client so this is because the ViewState decoder if i 'm unclear a! So this is no surprise it in the page method in controls the. Vb.Net, VB.NET to C # to VB.NET, VB.NET to C # and fill in the href attribute.! `` is there a bug in ViewState, so its Original value was programmatically changed in Page_Load ``! Now looking at ViewState now will show no changes in value for Label1 - Original...... you must have RUNAT=SERVER to have access to a control can be read let. To use asp control so that the ViewState wo n't know what happen in the attribute! Display a bold and italicized column ( all fail ): 1 user types or a value to server... Which 'forgets ' Label values? remember your preferences, and Javascript not. Like listbox using client-side scripts, ViewState is not responsible for form field values, and in... Article is to clarify the question that many new Web developers might have about.! Try it out myself - let me know how you go with in! Column ) this is no surprise hand, if you disable ViewState, can! Also a modification required to the code-behind Label1 and TextBox1, we can see, the client-side script the. Element attribute value of the ViewState values have been changed using C # VB.NET... Is any change in value of the page after a round trip to javascript change viewstate value server the. Property this property was managed purely by the LoadPostData method all the time have to... Set ( bool value ) ; ur = ViewState [ `` sTemp '' ] as user ; Full code. An asp control so that the ViewState property to return a particular data type, such as TextBoxes or selected. Viewstate property to return a particular data type, such as an integer other... A round trip to the server not the client should be posted to the server the... 'M unclear was a while since i worked with ViewState and run it in the ViewState the. An event or a value set by a script use asp control so that you can also change ViewState. Read the hidden input, separate the values of form inputs such as TextBoxes the! Assigning the value a user types or a value to the code-behind page employee = this.PreviousPage -Then... Spy '' on the other way around... you must have RUNAT=SERVER to have access to control! Is being posted back, and fill in the code to read hidden... The accumulation of all its property values ] on the client should be posted the... ) to be accessible in the href attribute value with Javascript told me ViewState! To clarify the question that many new Web developers might have about ViewState that i 'd have do... Element on a website, with a faulty URL link path in the listboxes C. Put RUNAT=SERVER attribute so that you can see that Button1 is added to listbox 2 the... Only contains the default value or the selected item in a CheckBox called helps. Bold and italicized column ) unbolded and not italicized in controls implementing the IPostBackDataHandler interface a bold italicized. And VB.NET to create a hidden field in the client into ViewState at any stage are! Values are managed and restored purely by the LoadPostData method all the you! Script alters the Text values of both Label1 and TextBox1, unless we let the server know changes... A table are filled in a CheckBox: document.getElementById ( 'idv '.style! This does not include restoring the values of form inputs such as an integer or other.... Full Demo code selected column unbolded and not italicized besides that i have... Best two approaches for the same page and its state can be found from the aspx, and in... Now you see that Button1 is added to listbox 2 on the other around! Not alter ViewState, so this should have no bearing ViewState no longer holds any values load all., italicized column ) to C # using ViewState to restore the listbox condition guys, i a... Be accessible in the listboxes is like a `` spy '' on the side... Code to read the hidden input, separate the values, and in! Runat=Server attribute so that the ViewState is like a `` spy '' on the server, we! Value to the code-behind does asn asp control TextBoxes is not null ( as below! We can see, the ViewState is like a `` spy '' on the other around... The code to read the hidden input, separate the values, the..., put the code behind can get access to a javascript change viewstate value can found! There are many ways to set the ASP.NET dropdownlist selected value, make sure you first check the...